This invention pertains to the field of N-(4-piperidinyl)-N-phenylamides and -carbamates. In the prior art there may be found some N-(4-piperidinyl)-N-phenylamides and -carbamates having analgesic activity. Among other points of difference, the compounds of this invention differ from the prior art compounds by the nature of the R.sup.1 -substituent, present in the 4-position of the piperidine ring.
The closest prior art may be represented by the following references:
U.s. pat. No. 3,164,600; PA1 Riley et al., J. Pharm. Sci., 62, 983 (1973); and PA1 Belg. Pat. No. 818.989. PA1 A. a carboxylate radical represented by the formula ##STR2## wherein R.sup.2 is a member selected from the group consisting of lower alkyl, lower alkenyl and phenylmethyl; PA1 B. an alkanoyl radical represented by the formula ##STR3## wherein R.sup.3 is lower alkyl; and c. an oxymethyl radical represented by the formula EQU -CH.sub.2 -O-R.sup.4 PA1 wherein R.sup.4 is selected from the group consisting of hydrogen, lower alkyl, phenylmethyl and lower alkylcarbonyl; provided that PA1 a. a radical having the formula ##STR5## wherein R.sup.6 is lower alkyl or lower alkenyl; b. a radical of the formula ##STR6## wherein R.sup.3 is as previously defined; and c. a radical of the formula EQU --CH.sub.2 --O--R.sup.7 PA1 wherein R.sup.7 is hydrogen or lower alkyl; PA1 a. a radical of the formula ##STR12## wherein R.sup.2 is as previously defined; b. a radical of the formula ##STR13## wherein R.sup.3 is as previously defined; and c. a radical of the formula EQU --CH.sub.2 --O--R.sup.10 PA1 wherein R.sup.10 is a lower alkyl- or phenylmethyl radical, PA1 a. a radical of the formula ##STR46## wherein R.sup.2 is as previously defined; b. a radical of the formula ##STR47## wherein R.sup.3 is as previously defined; and c. a radical of the formula EQU --CH.sub.2 --O--R.sup.14 PA1 wherein R.sup.14 is selected from the group consisting of hydrogen, lower alkyl and phenylmethyl.